//秒转成时间
var secondToTime = function ( value ) {
  if ( typeof value != 'number' || isNaN( value ) ) {
    return value;
  };
  var number = Number( value );
  var minute = Math.floor( number / 60 );
  var second = Math.floor( number % 60 );
  if ( minute.toString( ).length < 2 ) {
    minute = '0' + minute;
  };
  if ( second.toString( ).length < 2 ) {
    second = '0' + second;
  };
  var str = minute + ':' + second;
  return str;
};